This application requests funds for the purchase of a new Nikon confocal microscope for use by neuroscientists and others at Tufts University School of Medicine (TUSM). An existing Leica TCS SP2 confocal microscope at Tufts is heavily used, eight years old, and frequently in need of repairs and/or maintenance. The new instrument will be added to an existing neuroscience microscopy facility within the Tufts Center for Neuroscience Research (CNR), which has served the imaging needs of more than 50 Tufts laboratories. Through the NINDS-funded CNR, an administrative structure and technical expertise are already in place to supervise, maintain and ensure equitable sharing of the new instrument (see appended letter from CNR Director, Dr. F. Rob Jackson). The new microscope will greatly expand confocal imaging capability for NIH- funded Tufts scientists. In addition, it will also provide a new capability - Total Internal Reflection Fluorescence (TIRF) microscopy - which is required by several investigators. There are more than 40 neuroscience research laboratories in 14 academic and clinical departments of Tufts University and the affiliated hospitals, and more than half of these laboratories use CNR core facilities. Work carried out in the cores during the last five years has resulted in hundreds of primary publications from Tufts scientists. Research performed by Tufts scientists has significance for understanding a broad spectrum of human diseases including neurological disorders. Neuroscience is a dominant theme of the medical school strategic plan (see executive summary at: ://www.tufts.edu/med/about/strategicplan/). The Tufts Department of Neuroscience recently recruited a new chair, Dr. Philip G. Haydon, and our neuroscience community is currently undergoing a major expansion (see appended letter of support from Dr. Philip Haydon). We anticipate that such growth will both enhance our community and increase the demand for state-of-the-art core facilities. Recognizing the essential role of CNR cores at Tufts, the University has provided significant institutional support to help establish and maintain them - amounting to approximately $1.2 M in funds and renovated space (described in Institutional Support section). The medical school and university also recently promised $200,000 in ongoing support to help fund a CNR pilot grant program which promotes use of shared core facilities (see appended letters from Dean Michael Rosenblatt and Vice Provost Peggy Newell). This application requests equipment funds to purchase a Nikon confocal microscope. Funds for this equipment are not available through our NINDS center grant as that is capped at $0.5M per year and almost all grant funds are required to pay service contracts and core manager and administrative salaries. Given the ongoing neuroscience expansion at Tufts, this upgrade is particularly important. The affordable research services provided by CNR cores will greatly augment the start-up packages provided to newly-hired Tufts neuroscientists and speed their integration into the local neuroscience community.